aunty
Before I get into answering the question regarding the natural antihistamine, I want to mention your need to make sure that any supplements you use come from an organic source. There is a difference between vitamin/mineral supplements of organic sources than those of a synthetic formulation. The human body is a "smart machine" and can discern the difference between the real (organic/natural) versus the fake (synthetic/manufactured copy). This does make a difference in how the body responds.
Chamomile is a natural antihistamine that provides anti-itch relief as a result of that property. The only dilemma with effectiveness is if your child has an allergen towards chamomile. This is the case for some people; however, and fortunately, this wasn't the case for my nieces. Other anti-itch relievers are calendula, lavender, colloidal oatmeal, comfrey and aloe. There are two other products on the market, containing some of these anti-itch ingredients, that you may want to examine further for yourself. They are "Eczema No More" and Weleda Baby products (in particular, "Weleda Baby Starter Kit"). I suggest a visit to your local Whole Foods Market or health store to examine these products up close. Here are the website references to further examine these two products:
http://www.Fonoils.com and
http://www.organicgiftshop.com
I know that you are aware that the topical treatment is just one part of the solution. You still need to rid the environment of the toxic irritant. I realize that you are taking steps to do just that; and as a result, will not further burden you with what I have already articulated in a previous post. I am aware that affordability and budget restraints have to also be considered in the process. Hopefully, you will be able to find an effective anti-itch reliever to help your child bear up in the interim.
aunty